Birth: The Science of Pushing

We’ve all seen the TV shows and movies where women are giving birth. The water breaks...and all hell breaks loose. There’s generally lots of yelling, panic, and terror. It’s what we’ve come to expect, right? No wonder women are afraid of giving birth. Who wouldn’t be?

But is the media’s portrayal of childbirth truly realistic?

Does birth have to be so out of control?

What do you do with these fears when you discover you’re pregnant?

I would encourage you to really take the time to sift through your own preconceived thoughts and beliefs about childbirth and question each one individually.

Think about giving birth. In the moment of truth, when you’re pushing out your baby in one glorious moment of power, what and who do you see around you? What do you hear? Is the room dark and quiet or bright and bustling? Are you afraid or courageous? What about the people around you? If there is a doctor or midwife, are they yelling or quiet? Are they touching you or hands-off? What about the support team? Who are they and what are they doing?

Ask yourself this: When I’m pushing out my baby, what do I want?

Let’s take a simple look at what goes on in the body during birth.

There are three stages of labor.

  • The First Stage is cervical dilation and effacement. Phase One is early labor when cervical dilation is below 4 cm and contractions are not steady or consistent. Phase Two is active labor when cervical dilation is 4+cm and contractions are steady and consistent. This stage ends when you are 10 cm dilated and fully effaced. This is the longest stage of labor and involves most of the contractions and pain associated with childbirth.

  • The Second Stage is the pushing stage. Phase One is the latent phase, which is a time of rest for the body before the woman feels the urge to push. Phase Two is the active pushing phase. Second Stage ends at the birth of the baby and can last anywhere from 20 minutes to 4 or more hours.

  • The Third Stage is the birth of the placenta. It usually takes an average of 30 minutes after the birth of the baby. It’s end signifies the end of childbirth.

What is fascinating to look at is the Latent Phase of the Second Stage of labor. Most people, including doctors, assume that as soon as a woman has reached 10 cm in dilation, she will be automatically “ready to push.” Regardless of how the woman is physically feeling, it is commonly thought that her body is prepared to push. The baby’s heart rate can usually decrease a bit during this phase, which concerns the doctor and looks like fetal distress. But more on that in a minute...

In births, I commonly hear from the OB, “Since you’re fully dilated, I want you to try to push on the next contraction and let’s see what happens.” Then the OB glares at the monitor and the woman’s vagina until the nurse says there’s a contraction. The woman then is instructed in what to do. Instead of being asked, she is told. Instead of being in charge of her birth, she is merely a bystander. Confused, yet wanting to do it correctly, the woman will often acquiesce to the shouts of, “push, push!”

So, let’s take a step back and look at the physiology of the Latent Phase of Second Stage of Labor. There are many systems at work and interplaying during childbirth.

The uterus is contracting in multiple directions for different purposes, and not always at a steady pace. Uterine muscles that run vertically contract during the dilation phase in order to pull up and open the cervix. After the uterus has fully opened and softened, and when left to its own devices without any interruption, the uterus will usually take a break to rest from the work of dilation. For anywhere from 10 minutes to 2 hours, a woman can seem to not be doing anything at all. Although she was just going through intense contractions without much break in between, the body can stop to rest. During the active pushing phase, completely different muscle fibers must fire. The vertical muscles turn off and the horizontal uterine muscles begin to contract and squeeze the baby down, around, and out.


Meanwhile, the baby is preparing their own body to survive outside the womb. Many systems have to turn on very quickly after birth, including the respiratory system. The baby must begin breathing on their own very quickly so that the lungs, blood, and heart can adjust to life without amniotic fluid and a placenta. In order to jump start this process, the baby’s heart rate will decrease slightly during the Latent phase of Second Stage. This sends a message to the baby’s brain to look for other sources of energy. Once the mother is pushing the baby out, contractions work to squeeze the amniotic fluid from the baby’s lungs. When mother and baby have been able to work together without much outside intervention, the baby is fully prepared to take that first gasp of air at birth. The Second Stage works miraculously as a sort of shock for the baby to jolt him into life as an independent being.
If your doctor is unaware of the reasons behind the Latent Phase of Second Stage, especially why the baby’s heart rate is decelerating, you may be told that your baby is not handling birth well anymore. Most commonly, you will be rushed into pushing before you are ready, which can cause your vaginal tissue to swell and get exhausted, often leading to forcep/vacuum extraction or cesarean birth.

In addition to the baby preparing to breathe without your help, your body and the baby are also working together to position the baby properly for birth. Below is a short video that illustrates the 7 Cardinal Movements of Labor, where the baby must rotate and descend to properly and efficiently exit the womb.

Copyright Doctors in Training 2010

When you understand all that’s going on with your body and the baby, of course you will want to be patient with the process. I would encourage you to talk to your doctor or midwife and discuss the Latent Phase of Second Stage. See how they respond. Are they frightened by those heart decels? Or do they have a good grasp on the physiology of birth and trust that it is a fine-tuned system that functions really well when left on its own? Ask how many of their births need forceps or vacuum. Ask if they would allow you to rest until you feel an urge to push. Ask if you can control the pushing instead of having a nurse prompt you.

After you’ve thought through your fears surrounding birth, you have the ability to address them head-on and work towards a birth story that will leave you empowered, strong, and respected.